Green Acropora Humilis
| Care Level
| Water Flow
Caring for thriving colonies of Acropora is often viewed as the pinnacle of reef keeping. These corals require a stable tank, high light levels and strong randomized flow. Successful Acropora husbandry is highly rewarding as these corals are known for being difficult to keep. There are over 150 species in this genus and they come in many different colourations and growth formations.
Acropora should be kept in a mature reef aquarium that has stable water parameters. While we have our preferred parameters for Alkalinity, Calcium, and Magnesium, Acropora will do far better in your system if you just focus on keeping the water chemistry stable. If your Alkalinity, Calcium, or Magnesium is out of line, our recommendation is to get it back to your target levels as slowly as possible.
The parameters we aim for are:
|| 8.3 dKH
|| 440 ppm
|| 1350 ppm
We maintain these levels by use of dosing pumps, with Brightwell Aquatics Reef Code A and Reef Code B.
It's important to understand that these are the levels that we aim for in our SPS system. However, that doesn't mean they are the right levels for your system. All aquariums are different and your system may naturally fall on a different balance. You're better off working with the balance your system tends towards than trying to force the same levels that we run.
In terms of flow, Acropora polyps should constantly be getting blown around in various directions. This is a good indication that you have the coral in strong randomized flow.
Good flow is also important to ensure the underside of the colony remains healthy. Often as Acropora colonies grow larger the sides that stop receiving light will lose their polyp extension and their colour. While this is inevitable to some extent, we find that stronger flow will keep the underside of the colony looking healthier and more colourful.
Acropora are among the most light-loving corals in our tanks. We always recommend placing them high up on the rockwork where they will receive plenty of light. There are some exceptions to this such as thin branching deepwater Acropora, but we aim to keep most of our Acropora in 200-350 PAR.
Too little light can cause Acropora to turn brown, if this happens raise the coral in your tank or increase your light intensity. This is a slow process, however, assuming it has good flow and your water chemistry is stable it will regain its colour.